阅读说明：本技术 一种基于弯制点密度的正畸弓丝变半径圆域划分方法 (Orthodontic arch wire variable-radius circular domain dividing method based on bending point density ) 是由 姜金刚 吴殿昊 曾阳 闵兆伟 郭亚峰 张永德 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种基于弯制点密度的正畸弓丝变半径圆域划分方法,它涉及正畸弓丝弯制技术领域,本发明针对弯制点角距比相对较小的一类正畸弓丝曲线,基于正畸弓丝曲线弯制点信息集、弯制点的机器人弯制信息集,结合机器人弯制正畸弓丝的运动特点,建立一种基于弯制点密度的正畸弓丝变半径圆域划分方法。技术要点为：将正畸弓丝曲线T转换为平面曲线T′；圆域限制参数的设定及简化；确定划分圆域的半径和圆心；定义合理密度弯制圆域；判断是否继续进行圆域划分；以圆域弯制点密度<Image he="58" wi="61" file="DDA0002519032460000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>为指标,将各圆域降序排列,规定圆域的弯制点顺序,输出最终弯制点弯制顺序T<Sub>1</Sub>和R<Sub>1</Sub>。本发明以变半径圆域划分区域,将圆域弯制点密度作为判断条件,可以提高正畸弓丝弯制规划的效率,避免了机器人弯制正畸弓丝过程中出现干涉的问题。(The invention discloses a variable-radius circular domain dividing method for an orthodontic arch wire based on bending point density, which relates to the technical field of bending of orthodontic arch wires. The technical points are as follows: converting the orthodontic arch wire curve T into a plane curve T'; setting and simplifying circle domain limiting parameters; determining the radius and the center of a circle to be divided; defining a reasonable density bending circular domain; judging whether to continue to divide the circular domain; with point density being bent in a circular region Arranging the circular fields in descending order as an index, defining the circular fieldsThe bending point sequence of (1) and outputting a final bending point bending sequence T 1 And R 1 . The invention divides the area by the variable radius circular area, takes the density of the bending points of the circular area as the judgment condition, can improve the efficiency of the bending planning of the orthodontic arch wire, and avoids the problem of interference in the process of bending the orthodontic arch wire by the robot.)

1. The method for dividing the variable-radius circular domain of the orthodontic arch wire based on the bending point density is characterized by comprising the following steps of: the method comprises the following concrete implementation processes:

step one, dividing data import in a variable radius circular domain and orthodontic arch wire curve conversion:

according to the orthodontic arch wire curve with i bending points of a patient, calculating and inputting an orthodontic arch wire curve bending point information set T ═ T₁，t₂，t₃，...，t_i}，t_i＝(x_i，y_i，z_i) ' coordinates of each orthodontic archwire curve bending point, at each bending point t_iThe upper robot executes different bending movements, and each orthodontic arch wire curve bending point t_iAll correspond to a bending information unit r of a bending point robot_iThe bending information set of the robot for inputting the bending points is R ═ R₁，r₂，r₃，...，r_i}，r_i＝(x_i，y_i，z_i，α_i) ' denotes the coordinates of the bending point and the bending angle of the robot at the time of bending the point, α_iActing on bending points t for the robot_iAn upper bending angle;

centralizing the information of the individualized orthodontic arch wire curve forming control point into the coordinate t of each bending point_i＝(x_i，y_i，z_i) ' z in_iAssigned a value of 0, i.e. z_iObtaining an orthodontic arch wire curve conversion plane orthodontic arch wire curve T' which is equal to 0;

step two, setting a circle domain limiting parameter:

defining the number of bending points in the circular region by symbolsIndicating the number of bending points in the circleIs a radius ofRound area a of_nThe number of inner bending points; defining the density of bending points in a circle by symbolsIndicating, circle domain bending dot densityIs a circular domain a_nInner partA bending point having a radius ofThe degree of compactness in the circular domain of (1) is specifiedDensity of bending points in circular areaUnit of (2) is one/mm²，Dividing a circle area a for the nth variable radius on the curve of the orthodontic arch wire_nThe radius value of (d); defining a bending point angular distance ratio, denoted by the symbol E, which is a quantitative description of the bending complexity of a single bending point, the bending point angular distance ratio of the jth bending point definingIn particular, due to the first bending point t₁Without bending, the bending point t is specified₁Has a bending point-to-angular distance ratio of E₁＝0，α_jTo act on the bending point t_jThe bending angle of the part is formed,indicating action at bending point t_iAt a bending distance, i.e. bending point t_j-1And t_jThe length of the curve section between the two sections, j is more than 1 and less than i, and the bending point density of the circular region is obtainedBending point-angle distance ratio E_jNumber of bending points in the harmony circle regionCollectively referred to as circular domain limiting parameters, the upper limit values of the circular domain limiting parameters are defined and setUpper limit value Q of_maxSetting upIs rho_maxSetting E_jUpper limit value E of_maxDuring the whole circle division process Q_max、ρ_maxAnd E_maxConstant, in particular Q_max5, aiming at the obtained orthodontic arch wire curve with i bending pointsCalculating the bending point angular distance ratio E of i bending points on the curve segment of the orthodontic arch wire_jBy comparison, E can be taken out_jMaximum value ofTo the conditionAnd (3) carrying out verification, specifically:

if true, each bending point on the orthodontic arch wire curve conforms to the bending point angular distance ratio E_jLess than or equal to upper limit value E of angular distance ratio of bending point_maxIt can be known that on the orthodontic arch wire curve containing i bending points, under the limiting condition of the number of the bending points, no matter any number of the bending points exist on the divided circular domain, the divided circular domain can still ensure that the total bending complexity is within an acceptable range, and the requirement of the bending system on the angle distance ratio of the bending points in the divided circular domain can be met, so that the influence of the tight angle distance ratio factor of the bending points does not need to be considered in the process of dividing the circular domain of the orthodontic arch wire curve meeting the requirement, and the method only uses the number of the bending points in the circular domainAnd circle bending point densityLimiting the divided circular domain according to the reference, and skipping to the third step;

step three, determining the radius and the circle center of the divided circle domain:

dividing the circular field to bend the point t_q+1Taking bending points t as starting points_q+1Andthe straight line segments between the two segments are sequentially marked as line segmentsSegment of lineMedium length is the longestLarge line segments are marked asNamely, it isRespectively representing line segments The length of the n-th circle segment a to be generated on the curve of the orthodontic arch wire_nIs a line segmentThe radius of the midpoint of (1) is a line segmentHalf of the lengthAt this time, exactly two bending points fall on the boundary line of the circular area, and the newly formed circular area a_nCan just divide the bending points preset in the step threeAll bending points on the orthodontic arch wire curve segment intersected by the specified circle domain boundary line are divided by the circle domain, when the generated circle domain boundary line passes through the bending points, the bending points are also divided by the circle domain, and the orthodontic arch wire curve segment where the divided bending points are located can not be divided by other circle domains any more;is initially ofn is initially 1, i.e. the 1 st circular domain a is first divided₁The bending points divided by the circle area are preset to reach the upper limit value, and the bending points which can be divided at the moment are t₁、t₂、t₃、t₄、t₅And t is₁To divide a circular domain a₁A starting point of (a);

step four, defining a reasonable density bending circular domain:

according toCalculating by straight line segmentIs the center of a circle, toDividing a circular field by radius_nCircular domain bending point density ofDetermine if there is

The method specifically comprises the following steps:

if it is notWhen it is true, straight line segments are used for explanationIs the center of a circle, toRadius-based circle bending point densityDoes not exceed the set upper limit value rho of the density of the round bending points_maxThen, the straight line segment will be usedIs the center of a circle, toThe divided circular area containing the curve segment of the orthodontic arch wire is defined as a reasonable density bending circular area a_nCalculating the number q of all bending points on the orthodontic arch wire curve which are divided by the bending circular domain with reasonable density, and skipping to the fifth step;

if it is notAre out of standing and existAt this time, the number of the circle domain bending points for dividing the circle domain is not less than 1, and then the number of the circle domain bending points is continuously reduced to divide the circle domain, so thatCalculating the number q of all bending points on the orthodontic arch wire curve, which are divided by the bending circular domain with reasonable density, and skipping to the third step;

if it is notAre out of standing and existTo explain this, the number of the circle bending points for dividing the circle is only 1, and will be represented by t_q+1As a circle center, with a bending point t_q+1To adjacent bending point t_q+2Half of the linear distance therebetweenGenerated for radiusThe divided circular area containing the curve segment of the orthodontic arch wire is defined as a reasonable density bending circular area a_nThen the reasonable density is bent to form a circular area a_nComprises only one bending point t_q+1Calculating the number q of all bending points on the orthodontic arch wire curve which are divided by the bending circular domain with reasonable density, and skipping to the fifth step;

step five, judging whether to continue to divide the circle domain:

judging whether the number q of all bending points on the orthodontic arch wire curve divided by the bending circular domain with reasonable density is equal to the number i of the bending points or not;

the method specifically comprises the following steps:

if the number q of all bending points divided by the bending circular domain with reasonable density on the orthodontic arch wire curve is not equal to the number i of the bending points, the circular domain division is continued, and n is equal to n +1, namely, the next circular domain is divided, at the moment,

if i-q is more than or equal to 5, the number of the remaining undivided bending points is not less than 5, and then orderWhen the next circle domain is divided for the first time, the bending point which can be divided by the circle domain is preset to just reach the upper limit value, and the step III is skipped;

if i-q is less than 5 and i-q is not equal to 1, indicating that the number of remaining undivided bending points on the curve of the orthodontic arch wire is less than 5 but more than 1, and then controllingWhen the next circular area is divided for the first time, the number of bending points which can be divided by the circular area is equal to the number of remaining non-divided bending points on the orthodontic arch wire curve, and the step is skipped to the step three;

if i-q is less than 5 and i-q is 1, the bending points remained on the curve of the orthodontic arch wire and not divided at the moment are only the last 1 bending points t_iWill be given by t_iAs the center of circle, with t_i-1And t_iHalf of the linear distance therebetweenThe divided circular area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable density bending circular area a_nThen the reasonable density is bent to form a circular area a_nComprises only one bending point t_iJumping to the step six;

if the number q of all bending points divided by the bending circular domain with reasonable density on the orthodontic arch wire curve is equal to the number i of the bending points, the bending points are divided by the bending circular domain with reasonable density, and a reasonable density bending circular domain information set A is output₁＝{a₁，a₂，...，a_nSkipping to the step six;

step six, outputting a final bending sequence:

calculating each reasonable density bending circle area (a)₁，a₂，...，a_n) Circular domain bending point density ofObtaining a circle domain bending point density information setComparing the circular region bending point densities of the bending circular regions with reasonable densities, and supposing to obtainThe dot density is formed by bending the circular regionN circular domains are arranged in descending order for the index, so that a descending order reasonable density bending circular domain information set A is obtained₁＝{a₃，a₁，...，a_sAt any one bending circle area, with a bending point angular distance ratio E_jArranging bending points divided by the circular area in a descending order for the index, defining the sequence of the bending points corresponding to the angle distance ratio of the descending order bending points as the bending sequence of the bending points of the circular area, and further obtaining the coordinate matrix T of the orthodontic arch wire curve forming control point₁＝{t₇，t₆，t₈，...，t_mAndrobot bending information set R₁＝{r₇，r₆，r₈，...，r_mWhere t is_mThe bending point with the minimum bending point angular distance ratio in the s-th reasonable density bending circle is shown, and the final bending point bending sequence T is output₁＝{t₇，t₆，t₈，...，t_m}、R₁＝{r₇，r₆，r₈，...，r_mAnd the program is ended.

Technical Field

The invention relates to a bending point density-based orthodontic arch wire variable-radius circular domain dividing method, and belongs to the technical field of orthodontic arch wire bending.

Background

The malocclusion deformity is the third major oral disease endangering human health, has higher morbidity, and in modern oral medicine, the fixed correction is a common and effective orthodontic treatment means, while the bending of an orthodontic arch wire is the key of the fixed correction technology.

In the process of bending the personalized orthodontic arch wire by the robot, interference may occur between the personalized orthodontic arch wire and the robot bending paw, namely the personalized orthodontic arch wire collides with the robot bending paw, and after the interference occurs, the bending precision of the personalized orthodontic arch wire is greatly influenced, so that the correction effect is influenced, and the bent personalized arch wire cannot be applied to clinical treatment; research shows that in the process of forward bending the individual orthodontic arch wire, the forward bending is to bend the unbent orthodontic arch wire into a complex formed arch wire, interference is often caused by unreasonable bending sequence of forming control points, the reasonable bending sequence of the forming control points can effectively avoid the occurrence of interference, and the obtaining of the reasonable bending sequence of the forming control points is a necessary premise for realizing digital bending of the orthodontic arch wire.

For the research of the dividing method of the orthodontic arch wire bending planning, an equal-radius circular domain dividing method is provided in an invention patent, a circular domain dividing method for the orthodontic arch wire bending planning, with an authorization publication number of CN107647925B, issued by the inventor, and the region division is carried out on an orthodontic arch wire curve, and finally each region is sequenced, so as to obtain the bending sequence of the final bending point, although the method has certain application value for the orthodontic arch wire bending planning, because the method only divides the orthodontic arch wire curve by an un-based homogenization standard, the divided circular domain interval usually has the condition that the density degree of the bending points is too large or too small, namely the divided interval does not fully consider the individualized characteristic of the distribution information of the bending points on the orthodontic arch wire curve, for example, the bending points on the individualized orthodontic arch wire of a patient often have relatively small bending difficulty of the bending points, when the individual orthodontic arch wire is divided into circular areas, the existing orthodontic arch wire forming control point bending sequence planning method is poor in rationality, and efficient digital bending of the individual orthodontic arch wire cannot be achieved, so that idle stroke invalid actions of a bending robot, mutual interference actions in the bending process and complex bending actions cannot be effectively avoided, the advantages of the bending robot cannot be maximized, and the bending efficiency cannot be obviously improved.

Disclosure of Invention

Aiming at the problems, the invention provides a method for dividing the variable-radius circular domain of the orthodontic arch wire based on the bending point density, which solves the problem that the prior orthodontic arch wire bending technical field lacks an efficient bending sequence planning method for the orthodontic arch wire with a relatively smaller bending point angle distance, so as to avoid the condition of larger density degree in the region when the bending points of the orthodontic arch wire with special attributes are divided, facilitate the reasonable planning of the bending sequence, avoid the interference condition in the bending process and further realize the efficient digital bending of the orthodontic arch wire.

A method for dividing an orthodontic arch wire variable-radius circular domain based on bending point density is specifically realized by the following steps:

step one, dividing data import in a variable radius circular domain and orthodontic arch wire curve conversion:

according to the orthodontic arch wire curve with i bending points of a patient, calculating and inputting an orthodontic arch wire curve bending point information set T ═ T₁，t₂，t₃，...，t_i}，t_i＝(x_i，y_i，z_i) ' coordinates of each orthodontic archwire curve bending point, at each bending point t_iThe upper robot executes different bending movements, and each orthodontic arch wire curve bending point t_iAll correspond to a bending information unit r of a bending point robot_iThe bending information set of the robot for inputting the bending points is R ═ R₁，r₂，r₃，...，r_i}，r_i＝(x_i，y_i，z_i，α_i) ' denotes the coordinates of the bending point and the bending angle of the robot at the time of bending the point, α_iActing on bending points t for the robot_iAn upper bending angle;

centralizing the information of the individualized orthodontic arch wire curve forming control point into the coordinate t of each bending point_i＝(x_i，y_i，z_i) ' z in_iAssigned a value of 0, i.e. z_iObtaining an orthodontic arch wire curve conversion plane orthodontic arch wire curve T' which is equal to 0;

step two, setting a circle domain limiting parameter:

defining the number of bending points in the circular region by symbolsIndicating the number of bending points in the circleIs a radius ofRound area a of_nThe number of inner bending points; defining the density of bending points in a circle by symbolsIndicating, circle domain bending dot densityIs a circular domain a_nInner partA bending point having a radius ofThe degree of compactness in the circular domain of (1) is specifiedDensity of bending points in circular areaUnit of (2) is one/mm²，Dividing a circle area a for the nth variable radius on the curve of the orthodontic arch wire_nThe radius value of (d); defining a bending point angular distance ratio, denoted by the symbol E, which is a quantitative description of the bending complexity of a single bending point, the bending point angular distance ratio of the jth bending point definingIn particular, due to the first bending point t₁Without bending, the bending point t is specified₁Has a bending point-to-angular distance ratio of E_i＝0，α_jTo act on the bending point t_jThe bending angle of the part is formed,indicating action at bending point t_iAt a bending distance, i.e. bending point t_j-1And t_jThe length of the curve section between the two sections, j is more than 1 and less than i, and the bending point density of the circular region is obtainedBending point-angle distance ratio E_jNumber of bending points in the harmony circle regionCollectively referred to as circular domain limiting parameters, the upper limit values of the circular domain limiting parameters are defined and setUpper limit value Q of_maxSetting upIs rho_maxSetting E_jUpper limit value E of_maxDuring the whole circle division process Q_max、ρ_maxAnd E_maxConstant, in particular Q_max5, aiming at the obtained orthodontic arch wire curve with i bending pointsCalculating the bending point angular distance ratio E of i bending points on the curve segment of the orthodontic arch wire_jBy comparison, E can be taken out_jMaximum value ofTo the conditionAnd (3) carrying out verification, specifically:

if true, each bending point on the orthodontic arch wire curve conforms to the bending point angular distance ratio E_jBending or lessUpper limit value E of point-angle distance ratio_maxIt can be known that on the orthodontic arch wire curve containing i bending points, under the limiting condition of the number of the bending points, no matter any number of the bending points exist on the divided circular domain, the divided circular domain can still ensure that the total bending complexity is within an acceptable range, and the requirement of the bending system on the angle distance ratio of the bending points in the divided circular domain can be met, so that the influence of the tight angle distance ratio factor of the bending points does not need to be considered in the process of dividing the circular domain of the orthodontic arch wire curve meeting the requirement, and the method only uses the number of the bending points in the circular domainAnd circle bending point densityLimiting the divided circular domain according to the reference, and skipping to the third step;

step three, determining the radius and the circle center of the divided circle domain:

dividing the circular field to bend the point t_q+1Taking bending points t as starting points_q+1Andthe straight line segments between the two segments are sequentially marked as line segmentsSegment of lineThe line segment with the largest middle length is recorded asNamely, it isRespectively representing line segments The length of the n-th circle segment a to be generated on the curve of the orthodontic arch wire_nIs a line segmentThe radius of the midpoint of (1) is a line segmentHalf of the lengthAt this time, exactly two bending points fall on the boundary line of the circular area, and the newly formed circular area a_nCan just divide the bending points preset in the step threeAll bending points on the orthodontic arch wire curve segment intersected by the specified circle domain boundary line are divided by the circle domain, when the generated circle domain boundary line passes through the bending points, the bending points are also divided by the circle domain, and the orthodontic arch wire curve segment where the divided bending points are located can not be divided by other circle domains any more;is initially ofn is initially 1, i.e. the 1 st circular domain a is first divided₁The bending points divided by the circle area are preset to reach the upper limit value, and the bending points which can be divided at the moment are t₁、t₂、t₃、t₄、t₅And t is₁To divide a circular domain a₁A starting point of (a);

step four, defining a reasonable density bending circular domain:

according toCalculating by straight line segmentIs the center of a circle, toDividing a circular field by radius_nCircular domain bending point density ofDetermine if there is

The method specifically comprises the following steps:

if it is notWhen it is true, straight line segments are used for explanationIs the center of a circle, toRadius-based circle bending point densityDoes not exceed the set upper limit value rho of the density of the round bending points_maxThen, the straight line segment will be usedIs the center of a circle, toThe divided circular area containing the curve segment of the orthodontic arch wire is defined as a reasonable density bending circular area a_nCalculating the number q of all bending points on the orthodontic arch wire curve which are divided by the bending circular domain with reasonable density, and skipping to the fifth step;

if it is notAre out of standing and existAt this time, the number of the circle domain bending points for dividing the circle domain is not less than 1, and then the number of the circle domain bending points is continuously reduced to divide the circle domain, so thatCalculating the number q of all bending points on the orthodontic arch wire curve, which are divided by the bending circular domain with reasonable density, and skipping to the third step;

if it is notAre out of standing and existTo explain this, the number of the circle bending points for dividing the circle is only 1, and will be represented by t_q+1As a circle center, with a bending point t_q+1To adjacent bending point t_q+2Half of the linear distance therebetweenThe divided circular area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable density bending circular area a_nThen the reasonable density is bent to form a circular area a_nComprises only one bending point t_q+1Calculating the number q of all bending points on the orthodontic arch wire curve which are divided by the bending circular domain with reasonable density, and skipping to the fifth step;

step five, judging whether to continue to divide the circle domain:

judging whether the number q of all bending points on the orthodontic arch wire curve divided by the bending circular domain with reasonable density is equal to the number i of the bending points or not;

the method specifically comprises the following steps:

if the number q of all bending points divided by the bending circular domain with reasonable density on the orthodontic arch wire curve is not equal to the number i of the bending points, the circular domain division is continued, and n is equal to n +1, namely, the next circular domain is divided, at the moment,

if i-q is more than or equal to 5, the number of the remaining undivided bending points is not less than 5, and then orderWhen the next circle domain is divided for the first time, the bending point which can be divided by the circle domain is preset to just reach the upper limit value, and the step III is skipped;

if i-q is less than 5 and i-q is not equal to 1, indicating that the number of remaining undivided bending points on the curve of the orthodontic arch wire is less than 5 but more than 1, and then controllingWhen the next circular area is divided for the first time, the number of bending points which can be divided by the circular area is equal to the number of remaining non-divided bending points on the orthodontic arch wire curve, and the step is skipped to the step three;

if i-q is less than 5 and i-q is 1, the bending points remained on the curve of the orthodontic arch wire and not divided at the moment are only the last 1 bending points t_iWill be given by t_iAs the center of circle, with t_i-1And t_iHalf of the linear distance therebetweenThe divided circular area generated for the radius and containing the curve segment of the orthodontic arch wire is defined as a reasonable density bending circular area a_nThen the reasonable density is bent to form a circular area a_nComprises only one bending point t_iJumping to the step six;

if the number q of all bending points divided by the bending circular domain with reasonable density on the orthodontic arch wire curve is equal to the number i of the bending points, the bending points are divided by the bending circular domain with reasonable density, and a reasonable density bending circular domain information set A is output₁＝{a₁，a₂，...，a_nSkipping to the step six;

step six, outputting a final bending sequence:

calculating each reasonable density bending circle region(a₁，a₂，...，a_n) Circular domain bending point density ofObtaining a circle domain bending point density information setComparing the circular region bending point densities of the bending circular regions with reasonable densities, and supposing to obtainThe dot density is formed by bending the circular regionN circular domains are arranged in descending order for the index, so that a descending order reasonable density bending circular domain information set A is obtained₁＝{a₃，a₁，...，a_sAt any one bending circle area, with a bending point angular distance ratio E_jArranging bending points divided by the circular area in a descending order for the index, defining the sequence of the bending points corresponding to the angle distance ratio of the descending order bending points as the bending sequence of the bending points of the circular area, and further obtaining the coordinate matrix T of the orthodontic arch wire curve forming control point₁＝{t₇，t₆，t₈，...，t_mAnd robot bending information set R₁＝{r₇，r₆，r₈，...，r_mWhere t is_mThe bending point with the minimum bending point angular distance ratio in the s-th reasonable density bending circle is shown, and the final bending point bending sequence T is output₁＝{t₇，t₆，t₈，...，t_m}、R₁＝{r₇，r₆，r₈，...，r_mAnd the program is ended.

The invention has the beneficial effects that:

1. aiming at a circular domain dividing method, the invention provides a bending point angular distance ratio E_jThe bending complexity of a single bending point is quantitatively described and E is set_jUpper limit value E of_maxIn advance of division into circular regionsVerifying the maximum bending point angular distance ratio of the bending points on the curve of the orthodontic arch wireNo greater than upper limit E of bending point angular distance ratio_maxThe bending point angular distance ratio of each bending point on the curve of the orthodontic arch wire can be obtainedThe method meets the set requirement, avoids unreasonable planning of the overall bending sequence on the divided circle domain due to the fact that the angular distance ratio of the single bending point does not meet the set requirement, provides constraint of precondition for the method, and further improves the operability and accuracy of the method.

2. Compared with the invention patent ' a plane variable-radius circular domain dividing method for orthodontic arch wire bending planning ', which is filed by the inventor on the same day ', E_jThe proposal increases the constraint condition of dividing the bending circular area on the curve of the orthodontic arch wire, because the bending point angular distance ratio E of each bending point before division_jThe integral judgment is carried out, so that the sum of the bending point-angular distance ratio of the circular domain is omitted in the process of dividing the circular domainSo that the circle division process is based entirely on the circle bending point densityThe method can complete the bending point division of the orthodontic arch wire curve of a specific category by adopting the combined action of specific circular domain limiting parameters, and provides a new division thought for the bending point division method of the orthodontic arch wire curve.

3. Compared with the invention patent of ' a method for dividing the variable-radius circular domain of the orthodontic arch wire based on the bending point-angle distance ratio ' and the bending point-angle distance ratio ', both methods are suitable for the one with special attributeThe method is based on the premise that the angle distance ratio of each bending point meets the set requirement, and then the number of the bending points in the circular domain is only usedSum of bending point and angular distance ratio of sum circleAs the basis for dividing the bending circular domain, the method emphasizes on the premise that the density of unit bending points meets the set requirement, and further, the number of the bending points in the circular domain is only usedAnd circle bending point densityAs a basis for dividing the bending circular domain, the two methods have different application conditions when the orthodontic arch wire bending sequence planning is carried out, so that the method is mutually compensated with the other method, and further a series of methods for the orthodontic arch wire bending sequence planning are perfected.

4. After all bending points are divided, the invention uses the circle domain bending point density defined aiming at the circle domain divisionThe n circular areas are subjected to descending order arrangement for indexes to obtain an information set of descending order reasonable density bending circular areas, any bending circular area is specified, the bending sequence of the bending points in the circular areas is defined according to the sequence of the bending points corresponding to the descending order bending point angular distance ratio, the arrangement of the bending sequence of each bending point has a specific meaning, the determined bending sequence of each bending point is ensured, and the operability and the accuracy of the orthodontic arch wire bending planning are improved.

5. Compared with the invention patent of CN107647925B, the invention provides a circle domain dividing method for orthodontic arch wire bending planning, which is based on the division of the circle domain with variable radius, fully considers the individual characteristics of the distribution information of the bending points on the curve of the orthodontic arch wire for the arch wire with specific attributes, i.e. the bending difficulty of each bending point on the individual orthodontic arch wire of a patient is relatively small, the bending point angular distance ratio of each bending point is smaller than the specified upper limit value, provides a circle domain limiting parameter for dividing the curve of the orthodontic arch wire, so that the dividing process is not divided by a non-basis homogenization standard, but the radius of the divided circle domain is continuously changed to meet the specification of the circle domain parameter, a series of variable radius bending circle domains based on the bending point density are generated, and the rationality of the orthodontic shaping control point bending sequence planning method is improved, the idle stroke invalid action, the mutual interference action in the bending process and the complex action of the bending motion of the bending robot are effectively avoided, the maximization of the advantages of the bending robot is fully exerted, and the bending efficiency is obviously improved.

Drawings

For ease of illustration, the invention is described in detail by the following detailed description and the accompanying drawings.

FIG. 1 is a flow chart of a method for dividing a variable-radius circular domain of an orthodontic arch wire based on bending point density;

fig. 2 is a schematic view of distribution of individual orthodontic arch wire bending points;

fig. 3 is a schematic diagram of an individual orthodontic arch wire curve divided by the variable radius circular domain of the orthodontic arch wire based on the bending point density;

the specific implementation mode is as follows:

for the purposes of promoting a clear understanding of the objects, aspects and advantages of the invention, reference will now be made to the following description of the preferred embodiments illustrated in the accompanying drawings, with the understanding that the description is illustrative only and is not intended to limit the scope of the invention, and that the following description will omit descriptions of well-known structures and techniques in order to avoid unnecessarily obscuring the concepts of the invention.